Voltaic transmitting-telephone



A. K. EATON. VoltaieTransmitting Telephone.

No. 223,718. Patented Jan. 20, I880.

; y w/45w N PETERS. FHOIO-UTHOGRAFHER, WASHINGTON. D C

UNITED STATES PATENT OFFICE.

VDLTAIC TRANSMITTING-TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 223,718,

Application filed November 1341879.

To all whom it may concern Be it known that I, ASAHEL K. EATON, of Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Voltaic Transmitting- Telephones; and I do hereby declare the following to be'a full, clear, and exactdescription of the invention, such as will enableothers skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification, in which- Figure 1 is a vertical central section of the telephone. Fig. 2 is a plan view of the back of the instrument.

My invention relates to the construction of i an efficientvoltaic transmitting-telephone; and

it'consists in supporting the differentiating button and connecting it with the contactpieces by means of a flexible elastic tube, and

- also in a diaphragm held by central pressure only.

Referring to the drawings, M 0 0 represent the month-piece of the telephone, having a vibrating diaphragm, A, of brass, iron, or other suitable material. The diaphragm is held in place by the spring R, which is fastened by thescrews K Gr, and presses upon an elastic circular cushihn, H.

E represents a contact-piece of brass faced on theupper end with platinum, and riveted at its lower extremity, I, to the diaphragm.

AboveE is a small cylinder or button, 0, (the composition of which is given in mypatent of May 28, 1879,) or its equivalent, and above this button a contact-piece of brass, D, faced with i. platinum. The button may be made of solid retort-carbon, if desired, with good results. These three pieces E D O are embraced and connected together bymeansof a short piece of indiarubber or other elastic tubing, F, the caliber of which is smaller than the diameter of the contact-pieces and button, so that when they are forced into the tube the contact-pieces and button are held as one piece, I

though not quite touching each other.

Pressing upon the upper end of the contactpiece D is another diaphragm, B, held in place dated January ao,1sso.

conductivity of the button 0. This transmit ter, having two diaphragms,may be converted.

into a duplex instrument, if desired, by the addition of a second moutl1piece,O M 0, represented in dotted lines. On the other hand, the instrument may be simplified by removing the plate B and allowing the spring/H to press directly upon the contact-piece D. In that case the wire 1? is connected with the spring .R; but I do not intend to claim this second plate or any of its adjuncts as part of the subject-matter of this specification, though I may make it the subject of an applicationifor a sep-' arate patent.

By the foregoing description it will be seen that there are here two contactpieces and a solid resistance-piece, all lnclosed and supported by an elastic tube that embraces them tightly enough to hold them in position, and

yet keep them from absolute contact witheach' other. By these means the button and con tact-pieces, though solid in themselves, are yet elastic as a whole, and the harshness of articulation caused by the friction involved in the use of solid supports is avoided.

It will be observed that if these solid contactpieces and the solid button be put into a hard non-elastic tube to make them work they would have to be put in loosely, which,in their operation, would cause a harsh jarring sound that would confuse the articulation, to avoid which the elastic tube is employed as a suplporter.

The diaphragm-plate A, instead of being held or secured at its periphery,is secured or held by a fastenin'gapplied to itscenter. In the drawings there is'a spring, R, reaching across the plate, that bears upon an elastic cushion set on the center of the plate around by the spring B, having an intervening elastic the bottomend of the contact-piece E, which cushion, H.

is riveted to the center of the plate. By these IOO ' means the plate, instead of being clamped at its periphery, is clamped or held at its ,cei1ter, leaving it entirely free to vibrate uniformly from center to-cireumference on all sides, and to expand and contract Without distortion but I do not claim, broadly, the useof a'spring for holding the diaphragm in place.

I do not claim a spring forming or carrying one electrode of the circuit of the telephone, and constantly pressing against the other electrode and the diaphragm, to maintain the required initial pressure between the electrodes.

Having described my invention, I claim 1. The combination of the contact-pieces and p 

